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Diffstat (limited to 'boost/asio/detail/strand_service.hpp')
-rw-r--r-- | boost/asio/detail/strand_service.hpp | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/boost/asio/detail/strand_service.hpp b/boost/asio/detail/strand_service.hpp new file mode 100644 index 0000000000..4206346585 --- /dev/null +++ b/boost/asio/detail/strand_service.hpp @@ -0,0 +1,142 @@ +// +// detail/strand_service.hpp +// ~~~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2012 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// +// Distributed under the Boost Software License, Version 1.0. (See accompanying +// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// + +#ifndef BOOST_ASIO_DETAIL_STRAND_SERVICE_HPP +#define BOOST_ASIO_DETAIL_STRAND_SERVICE_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include <boost/asio/detail/config.hpp> +#include <boost/asio/io_service.hpp> +#include <boost/asio/detail/mutex.hpp> +#include <boost/asio/detail/op_queue.hpp> +#include <boost/asio/detail/operation.hpp> +#include <boost/asio/detail/scoped_ptr.hpp> + +#include <boost/asio/detail/push_options.hpp> + +namespace boost { +namespace asio { +namespace detail { + +// Default service implementation for a strand. +class strand_service + : public boost::asio::detail::service_base<strand_service> +{ +private: + // Helper class to re-post the strand on exit. + struct on_do_complete_exit; + + // Helper class to re-post the strand on exit. + struct on_dispatch_exit; + +public: + + // The underlying implementation of a strand. + class strand_impl + : public operation + { + public: + strand_impl(); + + private: + // Only this service will have access to the internal values. + friend class strand_service; + friend struct on_do_complete_exit; + friend struct on_dispatch_exit; + + // Mutex to protect access to internal data. + boost::asio::detail::mutex mutex_; + + // Indicates whether the strand is currently "locked" by a handler. This + // means that there is a handler upcall in progress, or that the strand + // itself has been scheduled in order to invoke some pending handlers. + bool locked_; + + // The handlers that are waiting on the strand but should not be run until + // after the next time the strand is scheduled. This queue must only be + // modified while the mutex is locked. + op_queue<operation> waiting_queue_; + + // The handlers that are ready to be run. Logically speaking, these are the + // handlers that hold the strand's lock. The ready queue is only modified + // from within the strand and so may be accessed without locking the mutex. + op_queue<operation> ready_queue_; + }; + + typedef strand_impl* implementation_type; + + // Construct a new strand service for the specified io_service. + BOOST_ASIO_DECL explicit strand_service(boost::asio::io_service& io_service); + + // Destroy all user-defined handler objects owned by the service. + BOOST_ASIO_DECL void shutdown_service(); + + // Construct a new strand implementation. + BOOST_ASIO_DECL void construct(implementation_type& impl); + + // Destroy a strand implementation. + void destroy(implementation_type& impl); + + // Request the io_service to invoke the given handler. + template <typename Handler> + void dispatch(implementation_type& impl, Handler handler); + + // Request the io_service to invoke the given handler and return immediately. + template <typename Handler> + void post(implementation_type& impl, Handler handler); + +private: + // Helper function to dispatch a handler. Returns true if the handler should + // be dispatched immediately. + BOOST_ASIO_DECL bool do_dispatch(implementation_type& impl, operation* op); + + // Helper fiunction to post a handler. + BOOST_ASIO_DECL void do_post(implementation_type& impl, operation* op); + + BOOST_ASIO_DECL static void do_complete(io_service_impl* owner, + operation* base, const boost::system::error_code& ec, + std::size_t bytes_transferred); + + // The io_service implementation used to post completions. + io_service_impl& io_service_; + + // Mutex to protect access to the array of implementations. + boost::asio::detail::mutex mutex_; + + // Number of implementations shared between all strand objects. +#if defined(BOOST_ASIO_STRAND_IMPLEMENTATIONS) + enum { num_implementations = BOOST_ASIO_STRAND_IMPLEMENTATIONS }; +#else // defined(BOOST_ASIO_STRAND_IMPLEMENTATIONS) + enum { num_implementations = 193 }; +#endif // defined(BOOST_ASIO_STRAND_IMPLEMENTATIONS) + + // Pool of implementations. + scoped_ptr<strand_impl> implementations_[num_implementations]; + + // Extra value used when hashing to prevent recycled memory locations from + // getting the same strand implementation. + std::size_t salt_; +}; + +} // namespace detail +} // namespace asio +} // namespace boost + +#include <boost/asio/detail/pop_options.hpp> + +#include <boost/asio/detail/impl/strand_service.hpp> +#if defined(BOOST_ASIO_HEADER_ONLY) +# include <boost/asio/detail/impl/strand_service.ipp> +#endif // defined(BOOST_ASIO_HEADER_ONLY) + +#endif // BOOST_ASIO_DETAIL_STRAND_SERVICE_HPP |